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Home :: Cancer Medicines and Drugs :: Antimetabolites
Antimetabolites
Antimetabolites are usually structural analogues of naturally occurring metabolites that interfere with normal synthesis of nucleic acids by falsely substituting purines and pyrimidines in metabolic pathways. Antimetabolites can be divided into:
- Folic acid antagonist , e.g. methotrexate. This is structurally very similar to folic acid and binds preferentially to dihydrofolate reductase, the enzyme responsible for the conversion of folic acid to folinic acid. It is used widely in the treatment of solid tumours and haematological malignancies, and also has a role as an immunosuppressant in non-malignant conditions such as rheumatoid arthritis.
- Pyrimidine antagonists , e.g. 5-fluorouracil, cytosine arabinoside (cytarabine) and gemcitabine. 5-Fluorouracil consists of a uracil molecule with a substituted fluorine atom. It acts by blocking the enzyme thymidylate synthetase which is essential for pyrimidine synthesis. 5-Fluorouracil has a major role in the treatment of solid tumours, particularly gastrointestinal cancers. Cytosine arabinoside is used almost exclusively in the treatment of acute myeloid leukaemia where it remains the backbone of therapy while its analogue gemcitabine is proving useful in a number of solid cancers such as lung and ovary.
- Purine antagonists , e.g. 6-mercaptopurine and 6-thioguanine, which are both used almost exclusively in the treatment of acute leukaemia.
Cancer Tip |
Fruit and vegetable consumption may not significantly reduce breast cancer risk, but fruits and vegetables contain phytochemicals and antioxidants that may be protective against other cancers and heart disease. A minimum of five servings per day is recommended.
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Health Tip |
Make sure your body temperature doesn’t fall below the normal range. Inadequate heating can result in hypothermia which is a common cause of confusion.
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Mesothelioma Information
